Free Lean Six Sigma Green Belt DMAIC: Improve and Control Questions and Answers — Questions and Answers
Question 1: A project team has successfully identified several potential solutions to reduce shipping errors. To objectively decide which solution to implement, they need to evaluate each option against criteria such as cost, implementation difficulty, and potential impact. Which tool is most appropriate for this task?
- Fishbone Diagram
- Control Chart
- Solution Selection Matrix (Correct answer)
- 5 Whys
Correct answer: Solution Selection Matrix
A Solution Selection Matrix (also known as a Pugh Matrix or prioritization matrix) is a tool used in the Improve phase to systematically evaluate multiple proposed solutions against a set of established criteria. This allows the team to make a data-informed decision rather than relying on opinion.
Question 2: Which of the following describes the primary purpose of conducting a pilot study during the Improve phase of a DMAIC project?
- To identify the root causes of the problem being addressed
- To validate the financial savings of the project for the final report
- To create the final control plan and hand it off to the process owner
- To test a proposed solution on a small scale to manage risk before a full-scale rollout (Correct answer)
Correct answer: To test a proposed solution on a small scale to manage risk before a full-scale rollout
A pilot is a small-scale trial of the proposed solution in a real-world environment. Its main purpose is to test the solution's effectiveness, identify any unforeseen problems, and refine the implementation plan, thereby reducing the risk associated with a full-scale deployment.
Question 3: A manufacturing team wants to prevent operators from installing a part backward. They redesign the part with an asymmetric tab that only allows it to be inserted in the correct orientation. This is an example of which lean technique?
- Kaizen
- Poka-Yoke (Correct answer)
- Kanban
- 5S
Correct answer: Poka-Yoke
Poka-Yoke is a Japanese term that translates to 'mistake-proofing.' The technique's purpose is to eliminate product defects by preventing, correcting, or drawing attention to human errors as they occur. Redesigning the part to make incorrect assembly impossible is a classic example of Poka-Yoke.
Question 4: After implementing an improvement to reduce the variability in the fill weight of a product, a team needs to monitor the process to ensure the gains are sustained. They will take samples of 5 boxes every hour and record their weights. Which SPC tool is MOST appropriate for monitoring the process average and variation over time?
- Pareto Chart
- Histogram
- p-Chart
- X-bar and R Chart (Correct answer)
Correct answer: X-bar and R Chart
An X-bar and R Chart is the correct choice for monitoring a process when dealing with continuous data (like weight) collected in subgroups of a consistent size (in this case, 5). The X-bar chart tracks the average of the subgroups, while the R chart tracks the variation (range) within the subgroups, making it ideal for this scenario.
Question 5: What is the primary function of a Control Plan in the final phase of a DMAIC project?
- To document the brainstorming sessions from the Improve phase
- To provide a detailed summary of actions for maintaining the process improvements (Correct answer)
- To calculate the final Return on Investment (ROI) for the project sponsor
- To perform a final root cause analysis on any remaining issues
Correct answer: To provide a detailed summary of actions for maintaining the process improvements
The Control Plan is a critical document created in the Control phase that provides a written summary for the process owner on how to continue monitoring the improved process. It outlines the metrics to be tracked, the methods and frequency of measurement, and the reaction plan to follow if the process goes out of control, ensuring that the project gains are sustained over time.
Question 6: A project team is finalizing a Control Plan for an improved invoicing process. Which of the following elements is LEAST likely to be included in this document?
- A detailed Voice of the Customer (VOC) analysis from the Define phase (Correct answer)
- The key metrics to be monitored (e.g., 'invoice accuracy rate')
- The frequency of data collection (e.g., 'daily audit of 10 invoices')
- A reaction plan specifying actions if accuracy drops below 99%
Correct answer: A detailed Voice of the Customer (VOC) analysis from the Define phase
While the Voice of the Customer (VOC) analysis is critical in the Define phase to establish project goals, the detailed analysis itself is not a standard component of the Control Plan. The Control Plan focuses on the mechanics of sustaining the improved process: what to measure, how to measure it, and what to do if it deviates, rather than restating the initial problem analysis.
Free Lean Six Sigma Green Belt DMAIC: Improve and Control Questions and Answers
A project team has successfully identified several potential solutions to reduce shipping errors.
To objectively decide which solution to implement, they need to evaluate each option against criteria such as cost, implementation difficulty, and potential impact.
Which tool is most appropriate for this task?